


Sleepless Nights and Fantasies

by Strawberry_Requiem



Series: Submissive Dimitri Cinematic Universe [3]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Desk Sex, Explicit Sexual Content, F/M, Femdom, Older Characters, Roleplay, Soft Dimitri Alexandre Blaiddyd
Language: English
Status: Completed
Published: 2020-04-07
Updated: 2020-04-07
Packaged: 2021-03-01 18:14:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,505
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23521387
Author URL: https://archiveofourown.org/users/Strawberry_Requiem/pseuds/Strawberry_Requiem
Summary: Neither Dimitri not Byleth can sleep, so they decide to go for a walk throughout the grounds of Garreg Mach to pass the time. When their wandering leads them to the old Blue Lions classroom and Dimitri's schoolboy fantasies about Byleth surface, their shared insomnia becomes a little more interesting.
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth
Series: Submissive Dimitri Cinematic Universe [3]
Series URL: https://archiveofourown.org/series/1657717
Kudos: 149





	Sleepless Nights and Fantasies

It was hours until dawn and Dimitri couldn't sleep. 

Neither could Byleth, for that matter. She tried to fake it for a time, lying curled up at his side, body facing away from him so he couldn't see how her eyes were open and cause him worry. He had not been so careful as to feign sleep as she had, which was why, after about an hour of her faking, she rolled over and admitted her lie.

They talked for a time, Byleth with her head rested on his chest. Dimitri told her about some political meetings he had the day before, about the letter he received from Sylvain about how he and Mercedes were thinking of passing House Gautier to their eldest daughter, despite her lack of Crest. About how their son Aidan was impatiently waiting to be old enough to be a student at Garreg Mach. 

But, she was restless, as she always was on their sleepless nights together. So, Dimitri was not surprised when she suggested that they go for a walk and got out of bed so she could fumble around for her furs in the dark. 

Despite having spent half of every year in Garreg Mach since their marriage fifteen years ago, Dimitri always had a hard time envisioning how their chambers looked. Especially when he was searching for where he put his warmer clothes. 

Neither changed properly, only choosing to drape themselves in cloaks and furs before taking off hand in hand for the monastery proper. 

The guards that were stationed at the base of the stairs that led up into the Archbishop's chambers greeted them without a second glance. It was a common enough occurrence to see the King and Archbishop refuse to sleep in favor of midnight walks together that it had been mostly ignored. 

They walked in tandem, arm in arm. Byleth pointed out some flowers she thought were pretty. Dimitri smiled at each and made a mental note of them so he could have a bouquet made and placed in a vase within their chambers later; he liked doing little things like that for her, surprising her with gifts. 

Byleth squeezed his arm when their wandering led them to the grounds in front of the classrooms. A light breeze caused the banners in front of each to flutter and dance. She gestured towards them. "Do you want to go in? For old times' sake?"

There was a hint of mischief in her tone that was so tempting to Dimitri. Once Byleth set her mind to something, he knew she wouldn't be dissuaded. In many ways, he was the same way. But, he saw no harm in going into his old classroom, to see how it changed over the years and how the new crop of students at the Officer's Academy was learning. 

He nodded, and followed her inside. 

Not much had changed from the way he remembered it from when he was a student 20 years ago. The bench desks seemed to be the same, though a little worn from the age. Whomever the professor was for this group of students, they kept different diagrams on the blackboard than Byleth had, but he supposed it was a different crop of students with different needs. 

Byleth wandered the classroom, trailing her hands along the desks as she passed. Sylvain's, Ingrid's Felix's, Dedue's. She stopped at his old desk, turning, and with a slight smile, sat down on the bench seat. "Come sit with me."

Dimitri obeyed, sidling up to Byleth on the bench, finding it smaller than he remembered from his Academy days. Though, he supposed he had grown some in the twenty years, and he wasn't accustomed to sharing it with someone. 

She took his hand, lacing her fingers in his. 

"This takes me back," Dimitri said, looking over her face in an effort to read her thoughts, "it reminds me of when I was a young man, when I used to sit here and listen to your lectures."

"When you used to moon over me during class."

Heat rose to Dimitri's face. "You noticed that, Beloved?"

Byleth snorted. "It's hard to miss the crown Prince hanging on your every word and pretending like he didn't understand a subject that he did well in on tests so he could ask for your help privately after class."

He shuffled his feet anxiously. After fifteen years of marriage, his wife still managed to cause the butterflies to flutter around his stomach. "I was young and with a head filled with thoughts of my pretty Professor."

She unlinked their hands and placed one of hers on his thigh. "I wouldn't have acted on anything. I wasn't attracted to you until the war."

Dimitri nodded. "I always knew that; you were--are a good woman and wouldn't have taken advantage of my naivety or infatuation," he placed one of his hands atop of the one on his thigh, "still, I had silly schoolboy fantasies about you."

"What sort of fantasies?" 

He turned away, embarrassed, "The sort young men have."

They weren't something he talked about, not with anyone except Sylvain for the sheer fact that Sylvain probably had similar fantasies, if not about Byleth, than for others. As long ago as it was, Dimitri vividly remembered those sleepless nights of being consumed with thoughts of Byleth, thoughts of Byleth's chest brushing against him while she checked over his shoulder at his work. Thoughts of her intoxicating smell. Of how soft her lips must have been. How soft _other_ parts of her must have been. He knew, now as a husband, these sort of thoughts were nothing to be ashamed of, it was merely a product of still desiring his wife. But back then, back when she was nothing more to him than a Professor, he always felt this guilt about wanting her like that.

Some of that surfaced then.

"Dimitri, we have two children together; we can talk freely about these things." 

These were things Dimitri knew. They spoke of all sorts of things regarding the bedroom. Freely, unrestrained. Moreso when their marriage was young and they were still trying to learn how to best serve each other. Now, after all the years, the communication was less a necessity to teach and learn, but out of a desire for it. He knew, after all this time, how to touch her to bring her to climax without need for instruction. And she knew his body better than she knew herself at times.

Still, at that moment, he felt like little more than a flustered teenager reliving his adolescent crush on his Professor. 

"If you would rather not tell me, it's fine. I didn't mean to pry."

Dimitri shook his head. "No, it's fine. It was that something about being in the classroom with you reminded me of my Academy days. Of being that boy all those years ago who pretended to not grasp a concept in class so that he could have a moment alone with his instructor."

Byleth's hand inched up his thigh and inward. 

"Kind of like right now?"

"Beloved, I-"

Before Dimitri had a chance to finish what he meant to say, Byleth stifled his words with a kiss. He was drunk on her in a matter of moments. Desperate, he clutched for the back of her head, nestling his hand in her hair where her head met her neck. 

As tired as he was, Dimitri wanted whatever she was proposing. 

"It's time for your lance training." Her tone was low, hardly above a whisper. Dimitri had to strain himself to hear her properly. 

Lance training. He knew _exactly_ what was being implied. Still, he was eager to play the part of the wide-eyed student in the game she had suggested. 

"Lance training?" He tried his best to keep the excitement out of his tone.

Byleth nodded slowly. "I'll show you proper lance handling and maintenance techniques."

Dimitri watched her as he unbuttoned his pajama pants and shimmied them down a bit, giving her easy access to what she wanted within them. Whatever she desired, he would give it to her. 

Her hand sunk into his pants and pulled his cock out. Dimitri sighed, relishing in the feeling of her skin on his. He wasn't hard, not yet, but everything about Byleth always felt good. 

"You need to properly maintain your weapon if it's going to last." She was stroking him now, moving her hand slowly up and down his shaft. Dimitri's heart was pounding. His posture eased, head resting on her chest. He was submitting completely to her, to everything she had in store for him.

With her free hand, Byleth drew him in, pressing his head further into her chest. Her pace quickened.

Dimitri moaned. 

Already, he was getting hard. Something about being there with his Beloved, at his old desk in his old classroom, it heightened his excitement. He started picking at the buttons of her nightgown. When he got down to her navel, he pulled one of her breasts free and latched his mouth onto the nipple. Dimitri cinched one of his arms around her waist, and with his free hand, kneaded her other breast in his palm.

Byleth took him by the chin and pried him off her, tilting his head so that he could get a better look at her hand on his cock. 

"Pay attention. You're not going to learn anything if you're distracted."

Her commanding voice caused Dimitri's cock to jump to full attention in her hand. She smiled, her grip tightened, and her speed increased. Dimitri mouthed an obscenity. Byleth was so good. So wonderful. Her hands were still a bit rough from her life as a mercenary prior to becoming the Archbishop and his Queen, but he loved it. 

As lost as he was in the moment, Dimitri had noticed they hadn't closed the classroom door. He hesitated, "Beloved, the door."

"Who's going to stop us? You're the King and I'm the Archbishop." She ran her thumb along his slit as punctuation, a rare sort of seduction on her face that got his blood pumping whenever he saw it.

Byleth removed her hand from him. Then, she rose up and sat on the edge of the desk. She spread her legs and hiked up her nightgown. "It's time to review what you learned."

Dimitri spun around to see her properly. The crotch of her underwear was already damp from arousal. He ran a finger along with the wet fabric, teasing her a little before he got to work in bringing her satisfaction. Her green eyes were boring through him, watching his every move. Watching as he moved the thin strip of fabric aside and slipped his middle finger into her to the second knuckle.

Byleth gripped the edge of the desk but maintained eye contact. Dimitri swiped his tongue along his bottom lip and met her with the same fervor. He never wanted anything more than he wanted his wife, and that moment was a testament to that. 

He slipped a second finger in.

Her breath had gone irregular and ragged. Byleth's eyes were still trained on him, mouth agape. Dimitri wanted to kiss her so badly.

She was moaning, soft and sweet, the way she did when she was concerned they might get caught. Her breasts fell completely out of her open nightgown with a particularly harsh breath. He reached out for one of them as he sealed her mouth with a kiss. 

It was Byleth who broke the kiss. She nipped at his lip and wagged her finger in a chiding motion. Then, just as swift, she grabbed his wrist and pulled his fingers out of her. Dimitri watched, puzzled, not knowing what she planned on doing. He was about to question her when she pulled her underwear off completely and laid back on the desk.

"It's time for your Certification exam."

Dimitri was so hungry, so desperate. Just being around her made him mad with desire and every moment was a struggle against that need. But at the sight of her, flushed pink with her own arousal and spreading her legs to accommodate him, he simply could not resist.

He sank half his cock into her. Byleth mewled approvingly. She arched into him, taking more than he had given. 

She was so warm, so soft, so wet. Dimitri was lost to everything except Byleth. Being with her, making love with her, it was something that, even after all this time, never became old or boring to him. 

"B...Beloved…"

His pace quickened. Thrusts bringing him deeper into her.

Byleth tightened around him, keeping him where she wanted him. Whatever she wanted, Dimitri wanted in spades. He was hers, completely. 

"Like this...I want it like this…"

Goddess, she was like fire. Hot to the touch and just as intense. 

They kissed again and again, muffling their moans in each other's mouths. Thoughts of his schoolboy fantasies of Byleth came to the forefront along with the realization that this was _so_ much better than any of that. This was real. This was her underneath him, her hands snaking into his shirt and nails digging into his back. This was her moans laced with words of love, eyes locked on his. This was knowing that they were still so in love, enough to defile his old desk in his old classroom. 

Being with Byleth like this always made him feel like a younger man.

Dimitri was close. He focused his mind on his tasks for the morning, giving himself time to cool down a little so she could get there. Not that she needed it. Byleth was closer than he had been. He could tell; Dimitri knew her body well enough to feel it building in her.

But he was _close._ Closer than thinking of meetings and introducing himself to the new crop of Blue Lions and whatever he was trying to distract himself with could manage. His body was drenched with sweat, his thrusts were erratic. 

Four Saints, he _needed_ this woman.

"Beloved...I…"

"I know...I know...me too…"

The sensation built up in Dimitri's core, like her fire set him alight. His lips pressed into hers again, concealing his moans of her name from any unlikely onlooker. But, he continued, thrusting into her until he felt her nails break his skin and could hear her cry out for him.

* * *

Byleth was finishing buttoning up her nightgown when Dimitri looked at her. She smiled, the sort of smile that betrayed what they had just been up to. His stomach went up in butterflies again, resulting in him momentarily fumbling with the buttons of his pants before finding himself again. 

He finished up his pants and grabbed for Byleth's discarded furs, which he secured around her shoulders lovingly and gave her a sweet kiss. 

"Did I pass my certification exam?"

"What? Oh, right, " she cupped his face in her hands, "with flying colors, my love."

**Author's Note:**

> Thanks for reading!
> 
> [You can find me on Twitter!](https://www.twitter.com/queenofthisdick)


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